Anti-BCMA CAR antibodies, conjugates, and methods of use

Abstract

The invention provides improved methods for detecting anti-BCMA CAR expression on T cells.

The invention claimed is: 
     
       1. An antibody or antigen binding fragment thereof that binds an anti-BCMA scFv domain of an anti-BCMA CAR comprising a variable light chain comprising CDRL1-CDRL3 sequences set forth in SEQ ID NOs: 1-3 or 9-11; and a variable heavy chain comprising CDRH1-CDRH3 sequences set forth in SEQ ID NOs: 4-6 or 12-14. 
     
     
       2. The antibody or antigen binding fragment thereof of  claim 1 , wherein the antibody or antigen binding fragment thereof binds one or more epitopes of an anti-BCMA scFv sequence set forth in SEQ ID NO: 25. 
     
     
       3. The antibody or antigen binding fragment thereof of  claim 1 , comprising a variable light chain sequence having 90% amino acid identity to an amino acid sequence as set forth in SEQ ID NO: 7 or 15. 
     
     
       4. The antibody or antigen binding fragment thereof of  claim 1 , comprising a variable heavy chain sequence having 90% amino acid identity to an amino acid sequence as set forth in SEQ ID NO: 8, 16, or 24. 
     
     
       5. The antibody or antigen binding fragment thereof of  claim 1 , comprising a variable light chain sequence having 90% amino acid identity to an amino acid sequence as set forth in SEQ ID NO: 7 or 15; and a variable heavy chain sequence having 90% amino acid identity to an amino acid sequence as set forth in SEQ ID NO: 8, 16, or 24. 
     
     
       6. The antibody or antigen binding fragment thereof of  claim 1 , wherein the antibody or antigen binding fragment thereof is murine, human, humanized, or chimeric. 
     
     
       7. The antibody or antigen binding fragment thereof of  claim 1 , wherein the antibody or antigen binding fragment thereof is monoclonal. 
     
     
       8. The antibody or antigen binding fragment thereof of  claim 1 , wherein the antibody or antigen binding fragment thereof is selected from the group consisting of: a Fab′ fragments, F(ab′) 2  fragments, bispecific Fab dimers (Fab2), trispecific Fab trimers (Fab3), Fv, single chain Fv proteins (“scFv”), bis-scFv, (scFv) 2 , minibodies, diabodies, triabodies, tetrabodies, disulfide stabilized Fv proteins (“dsFv”), and single-domain antibody (sdAb). 
     
     
       9. A conjugate, comprising the antibody or antigen binding fragment thereof of  claim 1  and a detectable label. 
     
     
       10. The conjugate of  claim 9 , wherein the detectable label is selected from the group consisting of: a hapten, a fluorescent dye, a fluorescent protein, a chromophore, a metal ion, a gold particle, a silver particle, a magnetic particle, a polypeptide, an enzyme, a luminescent compound, or an oligonucleotide. 
     
     
       11. The conjugate of  claim 9 , wherein the detectable label is a dye selected from the group consisting of: AF350, AF405, AF488, AF500, AF514, AF532, AF546, AF555, AF568, AF594, AF610, AF633, AF635, AF647, AF680, AF700, AF710, AF750, AF790, and AF800. 
     
     
       12. The conjugate of  claim 11 , wherein the detectable label is AF488. 
     
     
       13. A composition comprising the antibody or antigen-binding fragment thereof of  claim 1 . 
     
     
       14. A kit comprising the antibody or antigen-binding fragment thereof of  claim 1 , and instructions for use.